Hydraulic fluids



United States Patent 3,282,847 HYDRAULIC FLUIDS Karl Schneider,Leverkusen, and Hans-Werner Kauczor, Cologne, Germany, assignors toFarbeufabriken Bayer Aktiengesellschaft, Leverkusen, Germany, acorporation of Germany No Drawing. Filed July 28, 1965, Ser. No. 475,571Claims. (Cl. 252-78) The present invention relates to hydraulic fluids;more particularly it concerns hydraulic fluids based on arylor alkylarylesters of phosphoric acid, which possess an active amount of the amidesproduced from aliphatic or araliphatic amines and halides of partiallyesterified phosphoric acid.

This application is a continuation-in-part application of our co-pendingapplication Serial No. 182,977, filed March 21, 1962, and now abandoned.

Suitable amides are for example obtainable by reacting, preferably in amolecular proportion of 1:24, phosphoric acid diphenyl estermonochloride, phosphoric acid octyl phenyl ester monochloride,phosphoric acid dicresyl ester monochloride, and phosphoric aciddicresyl ester monobromide with aliphatic or araliphatic amines, such ase.g. Z-ethylhexylamine, n-octylamine, di-n-butyl amine, dodecylamine,oleylamine, stearylamine, benzylamine, and w-phenyldodecylamine, withheating if required, in an inert organic solvent, in which thesimultaneously formed hydrochlorides of the amines are insoluble, forinstance in ligroin, removing the salts and'evaporating the solvent.

The content of the amides in the hydraulic fluids amounts in general to0.1 to 15 percent by Weight, preferably 0.5 to 5 percent by weight.

If desired, chlorinated hydrocarbons, such as chlorinated paraflin,chlorinated diphenyl, and chlorinated terphenyl, or polyethers, such asthose from tetrahydrofuran and 1,2-oxide compounds, can be added to thehydraulic fluids in order to improve the non-inflammability or theviscosity temperature characteristics. The hydraulic fluids can alsocontain further additives, usual for hydraulic fluids, e.g. stabilizers,thickeners, antifoaming agents, anticorrosives and de-emulsifiers.

The hydraulic fluids of the present invention possess outstandinglubricant properties. On account of the content of the amides hereinbefore defined only very small frictional forces are set up even in therange of boundary lubrication. The parts given in the following tableare by weight.

TABLE Friction in kg,

(I) Tricresyl phosphate 260 Mixture of 98 parts of tricresyl phosphateand 2 parts of the amide produced from phosphoric acid diphenyl estermonochloride and dodecylamine 150 (II) Mixture of 50 parts of tricresylphosphate and 50 parts of tetrachlorodiphenyl 240 Mixture of 49 parts oftricresyl phosphate, 49 parts of tetrachlorodiphenyl, and 2 parts of theamide produced from phosphoric acid diphenyl ester monochloride anddodecylamine 170 Measured at 1000 kg. applied pressure on theAlmen-Wieland machine. Cf. Zerbe, Mineraltile 'und verwaudte ProduktePatented Nov. 1, 1966 The amide applied was produced from phosphoricacid diphenyl ester monochloride and dodecylamine in the followingmanner:

Within one hour 670 g. (3.6 mol) of dodecylamine were added dropwise toa solution of 472 g. (1.75 mol) of phosphoric acid diphenyl estermonochloride in 500 com. of ligroin while the reaction temperature waskept at 3540 C. by cooling. Thereupon the reaction mixture was stirredat room temperature for a further three hours, then shaken three timeswith 2 normal sodium hydroxide solution and finally distilled in vacuo.After the solvent and the excess of dodecylamine were distilled off theamide produced distilled at 210-270" C./0.5 mm. Hg. The yield amountedto 823 g.

Similar favourable results are obtained if instead of the amide producedfrom phosphoric acid diphenyl ester monochloride and dodecylamine theother amides are applied which are obtainable in the same manner asherein before described from the amines and partially esterifiedphosphoric acid halides mentioned above.

We claim:

1. A fluid composition consisting essentially of (A) a hydraulic fluidconsisting of a member selected from the group consisting of aryl esterand an alkylaryl ester of phosphoric acid and (B) about .1-15 by weightof an amide additive obtained by reacting (a) a component selected fromthe group consisting of Z-ethyl hexylamine, n octylamine, di n butylamine, dodecylamine, oleyl amine, stearyl amine, benzylamine, andw-phenyldodecylamine with (b) a component selected from the groupconsisting of phosphoric acid diphenyl ester mono-chloride, phosphoricacid octyl phenyl ester monochloride, phosphoric acid dicresyl estermonochloride, and phosphoric acid dicresyl ester m-onobromide, the molarproportion of (b) to (a) being about 1:24.

2. The composition of claim 1 containing at least one additionaladditive in a flame-retarding amount, the additive being a memberselected from the group consisting of tetrachlorodiphenyl, and acopolymerization product of tetrahydrofuran, ethylene oxide and1,2-propylene oxide, said copolymerization product possessing an averagemolecular weight of 6000.

3. A fluid composition containing 98 parts of tricresyl phosphate and 2parts of the amide produced by reacting phosphoric acid diphenyl estermonochloride with dodecylamine.

4. A fluid composition containing 49 parts of tricresyl phosphate, 49parts tetrachlorodiphenyl, and 2 parts of the amide produced by reactingphosphoric acid diphenyl ester monochloride with dodecylamine.

3 5. A fluid composition containing 95 parts of diphenyl Xylenylphosphate; 3 parts of a polyether having an average molecular weight of6000 produced by copolymerization of (a) tetrahydrofuran (b) ethyleneoxide and 1,2-'

propylene oxide; and 2 parts of the amide produced by reactingphosphoric acid diphenyl ester monochloride with dodecylarnine.

References Cited by the Examiner UNITED STATES PATENTS 2,933,449 4/1960Moreton 25278 X 5 LEON D. ROSDOL, Primary Examiner.

JULIUS GREENWALD, ALBERT T. MEYERS,

10 R. D. LOVERING, Assistant Examiner.

Examiners.

1. A FLUID COMPOSITION CONSISTING ESSENTIALLY OF (A) A HYDRAULIC FLUIDCONSISTING OF A MEMBER SELECTED FROM THE GROUP CONSISTING OF ARYL ESTERAND AN ALKYLARYL ESTER OF PHOSPHORIC ACID AND (B) ABOUT .1-15% BY WEIGHTOF AN AMIDE ADDITIVE OBTAINED BY REACTING (A) A COMPONENT SELECTED FROMTHE GROUP CONSISTING OF 2-ETHYL HEXYLAMINE, N-OCTYLAMINE, DI-N-BUTYLAMINE, DODECYLAMINE, OLEYLAMINE, STEARYL AMINE, BENZYLAMINE, ANDW-PHENYLDODECYLAMINE WITH (B) A COMPONENT SELECTED FROM THE GROUPCONSISTING OF PHOSPHORIC ACID DIPHENYL ESTER MONO-CHLORIDE, PHOSPHORICACID OCTYL PHENYL ESTER MONOCHLORIDE, PHOSPHORIC ACID DICRESYL ESTERMONOCHLORIDE, AND PHOSPHORIC ACID DICRESYL ESTER MONOBROMIDE, THE MOLARPROPORTION OF (B) TO (A) BEING ABOUT 1:2-4.